While one’s body eventually clears itself of most viruses, others remain in the body for life. Those that stay in the body have the potential to cause intermittent infections or even life-threatening illnesses without intervention. However, those that leave the body may still cause lingering ill effects. Long COVID syndrome, for example, consists of an array of clinical symptoms that can decrease one’s quality of life and limit the ability to exercise, work, and even socialize.
Understanding what a virus is, how it enters the body, symptoms that can occur, and how to prevent infection improves one’s chance of preventing chronic conditions.
Viral infections: complications, concerns, and prevention
Viruses are everywhere and cause various symptoms, from the common cold and typical respiratory symptoms (coughing, sinus congestion, fever, achiness) to skin rashes (chickenpox), GI illness (vomiting, diarrhea), neurological symptoms (meningitis, brain fog, poor memory), and neuropsychiatric symptoms (mood disorders, insomnia, memory loss, agitation, hallucinations), among others.
Some viral infections are short-lived, while others remain with you for life. Still, with other viruses, while the virus itself leaves, it may cause chronic symptoms, as we are seeing more and more with long COVID cases.
What is a virus?
A virus is an organism, not visible to the naked eye, that infects a host. Without a host, such as a human, animal, or plant, a virus cannot reproduce. The virus is simply a protective shell (capsid) around genetic material (RNA or DNA), that can cause disease when it enters a host's cell. Examples include COVID-19, influenza (flu), chickenpox, herpes, HIV, measles, mumps, and rubella. Luckily, we have successful vaccines against many viruses, but not all.
What is a viral infection?
To put it simply, a viral infection arises from a virus, which causes symptoms that can lead to:
- Respiratory disease
- Gastrointestinal disease (vomiting, diarrhea, fever, nausea)
- Dermatological issues (skin problems like rashes and itchiness)
- Sexually transmitted infections (STIs)
- Immune system abnormalities
A virus must touch the host’s mucus membranes to spread. Mucous membranes are a key component of our immune system. Because they are found in the nose, mouth, throat, eyes, ears, genitalia, and anus, the virus can spread through various ways. This includes ingestion, respiratory exposure, and direct contact with the virus.
Do we need to treat viral infections?
Generally speaking, many viruses have no therapy available and need to run their course. Often, with viral infections, we simply treat the underlying symptoms, allowing the immune system time to clear the virus. This includes managing cold and flu-like symptoms, GI signs, and aches and pains with over-the-counter (OTC) and home remedies, including pain relievers, cold medicines, and more. Always check with a healthcare professional if you are unsure if you need medications (OTC or otherwise).
Some viruses may be treated with antiviral medications such as the ever-renowned Paxlovid® which became famous during the COVID-19 pandemic. This class of medicine works on the virus and may shorten the course of clinical symptoms, lessen your chance of severe illness, and reduce the risk of hospitalization.
A downside is that with some of these antiviral medications and some of the viral diseases, recurrence of clinical signs may be possible once the medication stops. This may be a rebound effect, though the exact science is still being evaluated. Based on current research, antivirals may or may not help prevent severe disease complications or long-term disease effects.
Another drawback is that these medications aren’t without side effects. Plus, not all individuals can take antiviral medications. Many antiviral medications interact negatively with numerous medicines, from asthma to heart medications. Talk to a healthcare specialist if you develop a viral infection and feel you should be on medication during the disease course.
Long-term viral complications
Some infections, viral or otherwise, are short-lived. They usually cause symptoms for 1–14 days and resolve on their own or with the help of an oral antiviral medication. However, some viruses can trigger changes after the virus has left the body (weeks to months to years later).
Potential ill effects from viruses long after they are gone may include digestive effects, neuropsychological symptoms, neurological effects, and cardiorespiratory effects.
Digestive symptoms can occur due to reduced gut movement in one or more parts of the GI tract, including the esophagus (esophageal dysmotility) or stomach (gastroparesis). Additional concerns include SIBO, or small intestinal bacterial overgrowth that develops as a result of physical damage to the intestines by the virus and/or due to the weakening of the immune system. Finally, some people may develop post-infection irritable bowel syndrome (IBS).
Neuropsychological symptoms post-viral infection vary but include problems with memory, mood disorders, trouble concentrating, and brain fog.
Neurological symptoms, including dizziness, pins and needles (numbness/tingling), or balance troubles, may develop.
Signs associated with cardiovascular and respiratory symptoms may overlap, including chest pain, shortness of breath, exercise intolerance, or elevated heart rate.
Long COVID specific symptoms
While some people can recover from COVID-19 after 3–14 days, others may show symptoms long after the body has cleared the virus. This may be due to long COVID or post-COVID syndrome, which may include various symptoms, including:
- Heart palpitations
- Increased heart rate
- Exercise intolerance
- Chronic fatigue
- Shortness of breath
- Chest pain
- Chronic pain
- Brain fog
- Sleep troubles
- Tingling/pins and needles
- Increased anxiety/depression
- GI effects
- Changes in menstrual cycle
- POTS (postural orthostatic tachycardia syndrome)
Keep in mind that there is not one specific diagnosis that encompasses all of these possible concerns. Further, no single test confirms signs are due to your previous COVID infection.
Persistent viral infections
Once we recover from a viral disease, we are cured, right? No, sadly, this isn’t true. While symptoms may resolve, some viral diseases remain in the body for life. Most notably, the human immunodeficiency virus (HIV) and herpesvirus. These can cause long-term symptoms (intermittent), sometimes brought on by stress, but managed with various medications and preventative therapies. Persistence of viral infection, even if an individual remains asymptomatic, may increase the risk of complications or other diseases in time.
HIV emerged in the 1980s. Thankfully, we now know much more about this once-lethal condition. Today, we have successful anti-retroviral therapies (ART) and pre-exposure prophylaxis (PrEP) medication options that help lessen the risk of contracting the illness, spreading it to others, and developing life-threatening AIDS (acquired immunodeficiency syndrome).
Chickenpox is generally a mild virus causing primarily irritating skin lesions and itchiness. This virus, now part of the common childhood vaccines, may trigger a change that affects the nervous system, called Shingles. While this is more commonly associated with individuals who developed the disease naturally, those vaccinated for chickenpox (a modified live vaccine) can also develop this complication. However, it is generally thought to be much more mild if it does occur in vaccinated individuals.
Are other viruses a problem?
Could other viral infections lead to chronic problems? Yes — likely, many viral diseases cause chronic ill effects. Still, because these signs show up months to years after a viral infection, we often don’t associate the viral infection with the subsequent signs.
Ongoing research continues to investigate possible chronic symptoms associated with the flu (influenza). A recent study by the Veterans Affairs St. Louis Health Care System and the Washington University School of Medicine in St. Louis suggests that long-fluoccurs in addition to the more well-studied post-COVID syndromes. Long-term effects on the lungs are primarily appreciated and attributed to previous/recent influenza infections. Additional research is needed to understand better how common long-flu problems are in the general population.
Preventing viral infections
Prevention of any infection is key. However, it is not always reasonable or possible, especially when one doesn’t even know they have been exposed. Still, practicing proper hygiene, staying home when ill, not being around sick individuals, cooking food fully, getting enough sleep, and eating a balanced diet can help lessen one’s chance of developing a viral infection. For those viruses that have a successful vaccination available, make sure to stay current with your boosters.
Dangers of viral infections
All infections, regardless of the cause (viral, bacterial, fungal, protozoal, etc.), have the potential for deadly effects. Viral infections alone may not be fatal, but in the right person, underlying conditions, genetic predispositions, certain viral strains, and other factors can lead to serious illness with long-lasting complications.
Sometimes, a virus remains in the body for life, while other times, the organism clears, but lingering effects remain. Complications from a viral illness can include secondary infections, including pneumonia, meningitis, or sepsis. Some viral conditions may require hospitalization, while others require just a day or two off from work and some rest.
The last words on viral infections
Most viral infections resolve without intervention. However, if you are sick for more than 3–5 days, are suffering from a very high fever that will not break, have underlying health conditions, or are at all concerned, seek medical attention.
Do not use supplements without consulting a healthcare provider, as not everyone is created equal. Many have no scientific evidence supporting use, can interact with medications, or worsen underlying conditions, and some may cause harm.
For common winter respiratory infections, especially those with a cough, you may be able to do a few home remedies to help you feel better while your body recovers. Generally, we have to wait out viral infections until our immune system does its job.
Complications can arise from viral infections, including secondary bacterial infections, pneumonia, SIBO, and more. Waiting too long to seek help may increase your risk of developing long-term chronic problems. However, the percentage of individuals who develop long-term issues relative to those who become infected is low. So do not fear that you will be sick for life.
Still, if you have had a recent viral infection and feel run down, achy, weak, or have GI issues like nausea, reflux, or bloating weeks to months after infection, you could have long-term viral complications and should seek professional advice.
How do you tell if a disease is viral or bacterial?
The way to identify the disease-causing clinical signs is via testing. Various tests exist for different viruses and bacteria. Based on clinical signs alone, one cannot always tell if something is viral. However, a large portion of respiratory infections and GI bugs are. Testing may not be necessary unless symptoms fail to respond promptly or there is concern for infection risk to others.
Are viral infections contagious?
Generally speaking, yes, viral infections are contagious. However, how we obtain viral infections varies from one virus to another. Some are much more contagious than others, some require direct contact with an individual’s bodily fluids, and others require simple aerosolization of saliva and contact time with an infected individual.
Do viral infections cause serious long-term health problems?
Most viruses do not contribute to chronic disease. However, there is always a risk of complications from any infection. Further, some viral infections, like COVID-19, have been shown to cause chronic syndromes. Finally, other infections, such as HIV and herpes, are never eliminated from the body. Instead, they must be managed and kept at bay.
Can viral infections lead to death?
Yes. Not all viruses are created equal in that some are more likely to cause death than others. Consider COVID-19 vs. chickenpox. However, the risk of death increases based on age (young and very old may be at higher risk), genetics, underlying health conditions, viral load, immune system function, vaccination status, and severity of the viral strain.
Viruses, small bundles of DNA or RNA, infect a host (e.g., human, animal, or plant) to cause infection.
Avoiding viral infections and obtaining vaccinations help prevent chronic long-term health issues. However, completely avoiding viral infections proves challenging unless we live in a bubble.
Some viruses like herpes and HIV remain in the body for life. In contrast, others are cleared once the immune system fights the infection.
Some viruses may trigger chronic symptoms, including digestive effects, neuropsychological symptoms, neurological effects, and cardiorespiratory effects.
Ongoing research confirms that long COVID/post-COVID syndromes exist. However, diagnosis is difficult, and treatment options are still being researched.
- The Lancet Infectious Diseases. Long-term outcomes following hospital admission for COVID-19 versus seasonal influenza: a cohort study.
- Cleveland Clinic. Virus.
- Nature Reviews Cardiology. Autonomic dysfunction and postural orthostatic tachycardia syndrome in post-acute COVID-19 syndrome.
- Psychiatry and Clinical Neurosciences. Neuropsychiatric aspects of long COVID: a comprehensive review.
- Centers for Disease Control and Prevention. Long COVID or post-COVID conditions.
- Gastroenterology Clinics of North America. Post-infection irritable bowel syndrome.
- Yale Medicine. What is Paxlovid rebound? 9 things to know.